2054084 - 16.64 - 14.48% tscrollx + 1 more (Linux) regression on Tue July 7 2026

Status: RESOLVED WORKSFORME

(Core :: Graphics: WebRender, defect)

Description

[Performance Sheriff Bot]

Perfherder has detected a talos performance regression from push 79a3125a8baae1d42cc2b98eedb448472eb3bc42. As author of one of the patches included in that push, we need your help to address this regression.

Please acknowledge, and begin investigating this alert within 3 business days, or the patch(es) may be backed out in accordance with our regression policy.

Regression	Test	Platform	Options	Absolute values [old vs new]
17%	tscrollx (doc)	linux2404-64-shippable	e10s fission stylo webrender-sw	0.69 -> 0.81
14%	tscrollx (doc)	linux2404-64-shippable	e10s fission stylo webrender-sw	0.69 -> 0.79

Support & Actionable Steps

For questions, please contact [e-mail]. You can also find help on Slack (#perf-help) or Matrix (#perftest).

Action guide details:

• See the guide to handling regression bugs for investigation steps.
• Review the alert summary for affected tests, graphs, and comparisons.
• Check the PerfCompare results.
• Tests on Try: Run all tests using ./mach try perf --alert 51362 (See documentation link for details).
• Profiling jobs: Trigger jobs from Treeherder job view or request them from [e-mail].

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 2050692

Comment 2

[Glenn Watson [:gw]]

I'll investigate this week.

Comment 3

[Glenn Watson [:gw]]

I've confirmed there's no extra rasterization or invalidation occurring. This appears to be a small regression showing up only when the apz.paint_skipping.enabled pref is enabled.

Comment 4

[Hiroyuki Ikezoe (:hiro)]

I think Glenn meant apz.paint_skipping.enabled is disabled since tscrollx_paint_skip is the one where apz.paint_skipping.enabled=true.